Irreversible processes in isolated systems

Abstract

The point of view is taken that the irreversibility paradox of Loschmitt and Zermelo arises because there are two valid transport equations, one causal, the other anticausal, each consistent with the fundamental equations of mechanics. From this point of view the problem of irreversibility is to characterize a given nonequilibrium distribution as to which transport equation it will obey. Using the transport theories of Kohn and Luttinger and of Van Hove, we obtain a statistical criterion capable of so characterizing distribution functions of both stationary and time varying types. We discuss the question of how experimental procedures consistently bring about a situation to which the causal transport equation applies; we answer the question for a very simple kind of experimental situation. © 1960 The American Physical Society.